Multi-radio coexistence

ABSTRACT

A method of wireless communication includes adjusting a channel quality indicator (CQI) to compensate for coexistence interference experienced between communication resources (such as an LTE radio and a Bluetooth radio). The CQI may be set to zero, falsely indicating to a serving enhanced NodeB that a UE is out of range, thereby creating a gap in LTE operation that may be used by an alternate radio access technology. To compensate for fluctuating interference, the CQI may be adjusted to incorporate average coexistence interference over a period of time. Alternatively, the CQI at a time may incorporate coexistence interference regardless of whether interference is experienced at that specific time. A CQI value may also be boosted to compensate for a CQI backoff. CQI may be adjusted to avoid a spiral of death effect.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/229,819, filed on Sep. 12, 2011, in the names of KADOUS et al., whichclaims the benefit of U.S. Provisional Patent Application No.61/385,371, filed on Sep. 22, 2010, in the names of KADOUS et al., thedisclosures of which are expressly incorporated herein by reference intheir entireties.

TECHNICAL FIELD

The present description is related, generally, to multi-radio techniquesand, more specifically, to coexistence techniques for multi-radiodevices.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustypes of communication content such as voice, data, and so on. Thesesystems may be multiple-access systems capable of supportingcommunication with multiple users by sharing the available systemresources (e.g., bandwidth and transmit power). Examples of suchmultiple access systems include code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, 3GPP Long Term Evolution (LTE)systems, and orthogonal frequency division multiple access (OFDMA)systems.

Generally, a wireless multiple-access communication system cansimultaneously support communication for multiple wireless terminals.Each terminal communicates with one or more base stations viatransmissions on the forward and reverse links. The forward link (ordownlink) refers to the communication link from the base stations to theterminals, and the reverse link (or uplink) refers to the communicationlink from the terminals to the base stations. This communication linkmay be established via a single-in-single-out, multiple-in-single-out ora multiple-in-multiple out (MIMO) system.

Some conventional advanced devices include multiple radios fortransmitting/receiving using different Radio Access Technologies (RATs).Examples of RATs include, e.g., Universal Mobile TelecommunicationsSystem (UMTS), Global System for Mobile Communications (GSM), cdma2000,WiMAX, WLAN (e.g., WiFi), Bluetooth, LTE, and the like.

An example mobile device includes an LTE User Equipment (UE), such as afourth generation (4G) mobile phone. Such 4G phone may include variousradios to provide a variety of functions for the user. For purposes ofthis example, the 4G phone includes an LTE radio for voice and data, anIEEE 802.11 (WiFi) radio, a Global Positioning System (GPS) radio, and aBluetooth radio, where two of the above or all four may operatesimultaneously. While the different radios provide usefulfunctionalities for the phone, their inclusion in a single device givesrise to coexistence issues. Specifically, operation of one radio may insome cases interfere with operation of another radio through radiative,conductive, resource collision, and/or other interference mechanisms.Coexistence issues include such interference.

This is especially true for the LTE uplink channel, which is adjacent tothe Industrial Scientific and Medical (ISM) band and may causeinterference therewith. It is noted that Bluetooth and some Wireless LAN(WLAN) channels fall within the ISM band. In some instances, a Bluetootherror rate can become unacceptable when LTE is active in some channelsof Band 7 or even Band 40 for some Bluetooth channel conditions. Eventhough there is no significant degradation to LTE, simultaneousoperation with Bluetooth can result in disruption in voice servicesterminating in a Bluetooth headset. Such disruption may be unacceptableto the consumer. A similar issue exists when LTE transmissions interferewith GPS. Currently, there is no mechanism that can solve this issuesince LTE by itself does not experience any degradation

With reference specifically to LTE, it is noted that a UE communicateswith an evolved NodeB (eNodeB; e.g., a base station for a wirelesscommunications network) to inform the eNodeB of interference seen by theUE on the downlink. Furthermore, the eNodeB may be able to estimateinterference at the UE using a downlink error rate. In some instances,the eNodeB and the UE can cooperate to find a solution that reducesinterference at the UE, even interference due to radios within the UEitself. However, in conventional LTE, the interference estimatesregarding the downlink may not be adequate to comprehensively addressinterference.

In one instance, an LTE uplink signal interferes with a Bluetooth signalor WLAN signal. However, such interference is not reflected in thedownlink measurement reports at the eNodeB. As a result, unilateralaction on the part of the UE (e.g., moving the uplink signal to adifferent channel) may be thwarted by the eNodeB, which is not aware ofthe uplink coexistence issue and seeks to undo the unilateral action.For instance, even if the UE re-establishes the connection on adifferent frequency channel, the network can still handover the UE backto the original frequency channel that was corrupted by the in-deviceinterference. This is a likely scenario because the desired signalstrength on the corrupted channel may sometimes be higher be reflectedin the measurement reports of the new channel based on Reference SignalReceived Power (RSRP) to the eNodeB. Hence, a ping-pong effect of beingtransferred back and forth between the corrupted channel and the desiredchannel can happen if the eNodeB uses RSRP reports to make handoverdecisions.

Other unilateral action on the part of the UE, such as simply stoppinguplink communications without coordination of the eNodeB may cause powerloop malfunctions at the eNodeB. Additional issues that exist inconventional LTE include a general lack of ability on the part of the UEto suggest desired configurations as an alternative to configurationsthat have coexistence issues. For at least these reasons, uplinkcoexistence issues at the UE may remain unresolved for a long timeperiod, degrading performance and efficiency for other radios of the UE.

SUMMARY

Offered is a method of wireless communication. The method includesaltering a channel measurement report to create a communication gap in afirst radio access technology. The method also includes communicatingusing a second radio access technology during the created communicationgap.

Offered is a method of wireless communication. The method includesaltering a channel measurement report of a first radio access technologybased on interference from a radio of a second radio access technology.The method also includes reporting the altered channel measurementreport to a serving cell.

Offered is an apparatus for wireless communication. The apparatusincludes means for altering a channel measurement report to create acommunication gap in a first radio access technology. The apparatus alsoincludes means for communicating using a second radio access technologyduring the created communication gap.

Offered is an apparatus for wireless communication. The apparatusincludes means for altering a channel measurement report of a firstradio access technology based on interference from a radio of a secondradio access technology. The apparatus also includes means for reportingthe altered channel measurement report to a serving cell.

Offered is a computer program product configured for wirelesscommunication. The computer program product includes a non-transitorycomputer-readable medium having non-transitory program code recordedthereon. The non-transitory program code includes program code to altera channel measurement report to create a communication gap in a firstradio access technology. The non-transitory program code also includesprogram code to communicate using a second radio access technologyduring the created communication gap.

Offered is a computer program product configured for wirelesscommunication. The computer program product includes a non-transitorycomputer-readable medium having non-transitory program code recordedthereon. The non-transitory program code includes program code to altera channel measurement report of a first radio access technology based oninterference from a radio of a second radio access technology. Thenon-transitory program code also includes program code to report thealtered channel measurement report to a serving cell.

Offered is an apparatus for wireless communication. The apparatusincludes a memory and a processor(s) coupled to the memory. Theprocessor(s) is configured to alter a channel measurement report tocreate a communication gap in a first radio access technology. Theprocessor(s) is also configured to communicate using a second radioaccess technology during the created communication gap.

Offered is an apparatus for wireless communication. The apparatusincludes a memory and a processor(s) coupled to the memory. Theprocessor(s) is configured to alter a channel measurement report of afirst radio access technology based on interference from a radio of asecond radio access technology. The processor(s) is also configured toreport the altered channel measurement report to a serving cell.

Additional features and advantages of the disclosure will be describedbelow. It should be appreciated by those skilled in the art that thisdisclosure may be readily utilized as a basis for modifying or designingother structures for carrying out the same purposes of the presentdisclosure. It should also be realized by those skilled in the art thatsuch equivalent constructions do not depart from the teachings of thedisclosure as set forth in the appended claims. The novel features,which are believed to be characteristic of the disclosure, both as toits organization and method of operation, together with further objectsand advantages, will be better understood from the following descriptionwhen considered in connection with the accompanying figures. It is to beexpressly understood, however, that each of the figures is provided forthe purpose of illustration and description only and is not intended asa definition of the limits of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, nature, and advantages of the present disclosure willbecome more apparent from the detailed description set forth below whentaken in conjunction with the drawings in which like referencecharacters identify correspondingly throughout.

FIG. 1 illustrates a multiple access wireless communication systemaccording to one aspect.

FIG. 2 is a block diagram of a communication system according to oneaspect.

FIG. 3 illustrates an exemplary frame structure in downlink Long TermEvolution (LTE) communications.

FIG. 4 is a block diagram conceptually illustrating an exemplary framestructure in uplink Long Term Evolution (LTE) communications.

FIG. 5 illustrates an example wireless communication environment.

FIG. 6 is a block diagram of an example design for a multi-radiowireless device.

FIG. 7 is graph showing respective potential collisions between sevenexample radios in a given decision period.

FIG. 8 is a diagram showing operation of an example Coexistence Manager(CxM) over time.

FIG. 9 is a block diagram illustrating adjacent frequency bands.

FIG. 10 is a block diagram of a system for providing support within awireless communication environment for multi-radio coexistencemanagement according to one aspect of the present disclosure.

FIG. 11 is a block diagram illustrating adjusted channel measurementreporting according to one aspect of the present disclosure.

FIG. 12 is a block diagram illustrating adjusted channel measurementreporting according to one aspect of the present disclosure.

FIG. 13 is a block diagram illustrating components for adjusted channelmeasurement reporting according to one aspect of the present disclosure.

FIG. 14 is a block diagram illustrating components for adjusted channelmeasurement reporting according to one aspect of the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure provide techniques to mitigatecoexistence issues in multi-radio devices, where significant in-devicecoexistence problems can exist between, e.g., the LTE and IndustrialScientific and Medical (ISM) bands (e.g., for BT/WLAN). As explainedabove, some coexistence issues persist because an eNodeB is not aware ofinterference on the UE side that is experienced by other radios.According to one aspect, the UE declares a Radio Link Failure (RLF) andautonomously accesses a new channel or Radio Access Technology (RAT) ifthere is a coexistence issue on the present channel. The UE can declarea RLF in some examples for the following reasons: 1) UE reception isaffected by interference due to coexistence, and 2) the UE transmitteris causing disruptive interference to another radio. The UE then sends amessage indicating the coexistence issue to the eNodeB whilereestablishing connection in the new channel or RAT. The eNodeB becomesaware of the coexistence issue by virtue of having received the message.

The techniques described herein can be used for various wirelesscommunication networks such as Code Division Multiple Access (CDMA)networks, Time Division Multiple Access (TDMA) networks, FrequencyDivision Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA)networks, Single-Carrier FDMA (SC-FDMA) networks, etc. The terms“networks” and “systems” are often used interchangeably. A CDMA networkcan implement a radio technology such as Universal Terrestrial RadioAccess (UTRA), cdma2000, etc. UTRA includes Wideband-CDMA (W-CDMA) andLow Chip Rate (LCR). cdma2000 covers IS-2000, IS-95 and IS-856standards. A TDMA network can implement a radio technology such asGlobal System for Mobile Communications (GSM). An OFDMA network canimplement a radio technology such as Evolved UTRA (E-UTRA), IEEE 802.11,IEEE 802.16, IEEE 802.20, Flash-OFDM®, etc. UTRA, E-UTRA, and GSM arepart of Universal Mobile Telecommunication System (UMTS). Long TermEvolution (LTE) is an upcoming release of UMTS that uses E-UTRA. UTRA,E-UTRA, GSM, UMTS and LTE are described in documents from anorganization named “3^(rd) Generation Partnership Project” (3GPP).CDMA2000 is described in documents from an organization named “3^(rd)Generation Partnership Project 2” (3GPP2). These various radiotechnologies and standards are known in the art. For clarity, certainaspects of the techniques are described below for LTE, and LTEterminology is used in portions of the description below.

Single carrier frequency division multiple access (SC-FDMA), whichutilizes single carrier modulation and frequency domain equalization isa technique that can be utilized with various aspects described herein.SC-FDMA has similar performance and essentially the same overallcomplexity as those of an OFDMA system. SC-FDMA signal has lowerpeak-to-average power ratio (PAPR) because of its inherent singlecarrier structure. SC-FDMA has drawn great attention, especially in theuplink communications where lower PAPR greatly benefits the mobileterminal in terms of transmit power efficiency. It is currently aworking assumption for an uplink multiple access scheme in 3GPP LongTerm Evolution (LTE), or Evolved UTRA.

Referring to FIG. 1, a multiple access wireless communication systemaccording to one aspect is illustrated. An evolved Node B 100 (eNodeB)includes a computer 115 that has processing resources and memoryresources to manage the LTE communications by allocating resources andparameters, granting/denying requests from user equipment, and/or thelike. The eNodeB 100 also has multiple antenna groups, one groupincluding antenna 104 and antenna 106, another group including antenna108 and antenna 110, and an additional group including antenna 112 andantenna 114. In FIG. 1, only two antennas are shown for each antennagroup, however, more or fewer antennas can be utilized for each antennagroup. A User Equipment (UE) 116 (also referred to as an Access Terminal(AT)) is in communication with antennas 112 and 114, while antennas 112and 114 transmit information to the UE 116 over an uplink (UL) 188. TheUE 122 is in communication with antennas 106 and 108, while antennas 106and 108 transmit information to the UE 122 over a downlink (DL) 126 andreceive information from the UE 122 over an uplink 124. In a frequencydivision duplex (FDD) system, communication links 118, 120, 124 and 126can use different frequencies for communication. For example, thedownlink 120 can use a different frequency than used by the uplink 118.

Each group of antennas and/or the area in which they are designed tocommunicate is often referred to as a sector of the eNodeB. In thisaspect, respective antenna groups are designed to communicate to UEs ina sector of the areas covered by the eNodeB 100.

In communication over the downlinks 120 and 126, the transmittingantennas of the eNodeB 100 utilize beamforming to improve thesignal-to-noise ratio of the uplinks for the different UEs 116 and 122.Also, an eNodeB using beamforming to transmit to UEs scattered randomlythrough its coverage causes less interference to UEs in neighboringcells than a UE transmitting through a single antenna to all its UEs.

An eNodeB can be a fixed station used for communicating with theterminals and can also be referred to as an access point, base station,or some other terminology. A UE can also be called an access terminal, awireless communication device, terminal, or some other terminology.

FIG. 2 is a block diagram of an aspect of a transmitter system 210 (alsoknown as an eNodeB) and a receiver system 250 (also known as a UE) in aMIMO system 200. In some instances, both a UE and an eNodeB each have atransceiver that includes a transmitter system and a receiver system. Atthe transmitter system 210, traffic data for a number of data streams isprovided from a data source 212 to a transmit (TX) data processor 214.

A MIMO system employs multiple (N_(T)) transmit antennas and multiple(N_(R)) receive antennas for data transmission. A MIMO channel formed bythe N_(T) transmit and N_(R) receive antennas may be decomposed intoN_(S) independent channels, which are also referred to as spatialchannels, wherein N_(S)≦min {N_(T), N_(R)}. Each of the N_(S)independent channels corresponds to a dimension. The MIMO system canprovide improved performance (e.g., higher throughput and/or greaterreliability) if the additional dimensionalities created by the multipletransmit and receive antennas are utilized.

A MIMO system supports time division duplex (TDD) and frequency divisionduplex (FDD) systems. In a TDD system, the uplink and downlinktransmissions are on the same frequency region so that the reciprocityprinciple allows the estimation of the downlink channel from the uplinkchannel. This enables the eNodeB to extract transmit beamforming gain onthe downlink when multiple antennas are available at the eNodeB.

In an aspect, each data stream is transmitted over a respective transmitantenna. The TX data processor 214 formats, codes, and interleaves thetraffic data for each data stream based on a particular coding schemeselected for that data stream to provide coded data.

The coded data for each data stream can be multiplexed with pilot datausing OFDM techniques. The pilot data is a known data pattern processedin a known manner and can be used at the receiver system to estimate thechannel response. The multiplexed pilot and coded data for each datastream is then modulated (e.g., symbol mapped) based on a particularmodulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM) selected for thatdata stream to provide modulation symbols. The data rate, coding, andmodulation for each data stream can be determined by instructionsperformed by a processor 230 operating with a memory 232.

The modulation symbols for respective data streams are then provided toa TX MIMO processor 220, which can further process the modulationsymbols (e.g., for OFDM). The TX MIMO processor 220 then provides N_(T)modulation symbol streams to N_(T) transmitters (TMTR) 222 a through 222t. In certain aspects, the TX MIMO processor 220 applies beamformingweights to the symbols of the data streams and to the antenna from whichthe symbol is being transmitted.

Each transmitter 222 receives and processes a respective symbol streamto provide one or more analog signals, and further conditions (e.g.,amplifies, filters, and upconverts) the analog signals to provide amodulated signal suitable for transmission over the MIMO channel. N_(T)modulated signals from the transmitters 222 a through 222 t are thentransmitted from N_(T) antennas 224 a through 224 t, respectively.

At a receiver system 250, the transmitted modulated signals are receivedby N_(R) antennas 252 a through 252 r and the received signal from eachantenna 252 is provided to a respective receiver (RCVR) 254 a through254r. Each receiver 254 conditions (e.g., filters, amplifies, anddownconverts) a respective received signal, digitizes the conditionedsignal to provide samples, and further processes the samples to providea corresponding “received” symbol stream.

An RX data processor 260 then receives and processes the N_(R) receivedsymbol streams from N_(R) receivers 254 based on a particular receiverprocessing technique to provide N_(R) “detected” symbol streams. The RXdata processor 260 then demodulates, deinterleaves, and decodes eachdetected symbol stream to recover the traffic data for the data stream.The processing by the RX data processor 260 is complementary to theprocessing performed by the TX MIMO processor 220 and the TX dataprocessor 214 at the transmitter system 210.

A processor 270 (operating with a memory 272) periodically determineswhich pre-coding matrix to use (discussed below). The processor 270formulates an uplink message having a matrix index portion and a rankvalue portion.

The uplink message can include various types of information regardingthe communication link and/or the received data stream. The uplinkmessage is then processed by a TX data processor 238, which alsoreceives traffic data for a number of data streams from a data source236, modulated by a modulator 280, conditioned by transmitters 254 athrough 254 r, and transmitted back to the transmitter system 210.

At the transmitter system 210, the modulated signals from the receiversystem 250 are received by antennas 224, conditioned by receivers 222,demodulated by a demodulator 240, and processed by an RX data processor242 to extract the uplink message transmitted by the receiver system250. The processor 230 then determines which pre-coding matrix to usefor determining the beamforming weights, then processes the extractedmessage.

FIG. 3 is a block diagram conceptually illustrating an exemplary framestructure in downlink Long Term Evolution (LTE) communications. Thetransmission timeline for the downlink may be partitioned into units ofradio frames. Each radio frame may have a predetermined duration (e.g.,10 milliseconds (ms)) and may be partitioned into 10 subframes withindices of 0 through 9. Each subframe may include two slots. Each radioframe may thus include 20 slots with indices of 0 through 19. Each slotmay include L symbol periods, e.g., 7 symbol periods for a normal cyclicprefix (as shown in FIG. 3) or 6 symbol periods for an extended cyclicprefix. The 2L symbol periods in each subframe may be assigned indicesof 0 through 2L-1. The available time frequency resources may bepartitioned into resource blocks. Each resource block may cover Nsubcarriers (e.g., 12 subcarriers) in one slot.

In LTE, an eNodeB may send a Primary Synchronization Signal (PSS) and aSecondary Synchronization Signal (SSS) for each cell in the eNodeB. ThePSS and SSS may be sent in symbol periods 6 and 5, respectively, in eachof subframes 0 and 5 of each radio frame with the normal cyclic prefix,as shown in FIG. 3. The synchronization signals may be used by UEs forcell detection and acquisition. The eNodeB may send a Physical BroadcastChannel (PBCH) in symbol periods 0 to 3 in slot 1 of subframe 0. ThePBCH may carry certain system information.

The eNodeB may send a Cell-specific Reference Signal (CRS) for each cellin the eNodeB. The CRS may be sent in symbols 0, 1, and 4 of each slotin case of the normal cyclic prefix, and in symbols 0, 1, and 3 of eachslot in case of the extended cyclic prefix. The CRS may be used by UEsfor coherent demodulation of physical channels, timing and frequencytracking, Radio Link Monitoring (RLM), Reference Signal Received Power(RSRP), and Reference Signal Received Quality (RSRQ) measurements, etc.

The eNodeB may send a Physical Control Format Indicator Channel (PCFICH)in the first symbol period of each subframe, as seen in FIG. 3. ThePCFICH may convey the number of symbol periods (M) used for controlchannels, where M may be equal to 1, 2 or 3 and may change from subframeto subframe. M may also be equal to 4 for a small system bandwidth,e.g., with less than 10 resource blocks. In the example shown in FIG. 3,M=3. The eNodeB may send a Physical HARQ Indicator Channel (PHICH) and aPhysical Downlink Control Channel (PDCCH) in the first M symbol periodsof each subframe. The PDCCH and PHICH are also included in the firstthree symbol periods in the example shown in FIG. 3. The PHICH may carryinformation to support Hybrid Automatic Repeat Request (HARQ). The PDCCHmay carry information on resource allocation for UEs and controlinformation for downlink channels. The eNodeB may send a PhysicalDownlink Shared Channel (PDSCH) in the remaining symbol periods of eachsubframe. The PDSCH may carry data for UEs scheduled for datatransmission on the downlink. The various signals and channels in LTEare described in 3GPP TS 36.211, entitled “Evolved Universal TerrestrialRadio Access (E-UTRA); Physical Channels and Modulation,” which ispublicly available.

The eNodeB may send the PSS, SSS and PBCH in the center 1.08 MHz of thesystem bandwidth used by the eNodeB. The eNodeB may send the PCFICH andPHICH across the entire system bandwidth in each symbol period in whichthese channels are sent. The eNodeB may send the PDCCH to groups of UEsin certain portions of the system bandwidth. The eNodeB may send thePDSCH to specific UEs in specific portions of the system bandwidth. TheeNodeB may send the PSS, SSS, PBCH, PCFICH and PHICH in a broadcastmanner to all UEs, may send the PDCCH in a unicast manner to specificUEs, and may also send the PDSCH in a unicast manner to specific UEs.

A number of resource elements may be available in each symbol period.Each resource element may cover one subcarrier in one symbol period andmay be used to send one modulation symbol, which may be a real orcomplex value. Resource elements not used for a reference signal in eachsymbol period may be arranged into resource element groups (REGs). EachREG may include four resource elements in one symbol period. The PCFICHmay occupy four REGs, which may be spaced approximately equally acrossfrequency, in symbol period 0. The PHICH may occupy three REGs, whichmay be spread across frequency, in one or more configurable symbolperiods. For example, the three REGs for the PHICH may all belong insymbol period 0 or may be spread in symbol periods 0, 1 and 2. The PDCCHmay occupy 9, 18, 32 or 64 REGs, which may be selected from theavailable REGs, in the first M symbol periods. Only certain combinationsof REGs may be allowed for the PDCCH.

A UE may know the specific REGs used for the PHICH and the PCFICH. TheUE may search different combinations of REGs for the PDCCH. The numberof combinations to search is typically less than the number of allowedcombinations for the PDCCH. An eNodeB may send the PDCCH to the UE inany of the combinations that the UE will search.

FIG. 4 is a block diagram conceptually illustrating an exemplary framestructure in uplink Long Term Evolution (LTE) communications. Theavailable Resource Blocks (RBs) for the uplink may be partitioned into adata section and a control section. The control section may be formed atthe two edges of the system bandwidth and may have a configurable size.The resource blocks in the control section may be assigned to UEs fortransmission of control information. The data section may include allresource blocks not included in the control section. The design in FIG.4 results in the data section including contiguous subcarriers, whichmay allow a single UE to be assigned all of the contiguous subcarriersin the data section.

A UE may be assigned resource blocks in the control section to transmitcontrol information to an eNodeB. The UE may also be assigned resourceblocks in the data section to transmit data to the eNodeB. The UE maytransmit control information in a Physical Uplink Control Channel(PUCCH) on the assigned resource blocks in the control section. The UEmay transmit only data or both data and control information in aPhysical Uplink Shared Channel (PUSCH) on the assigned resource blocksin the data section. An uplink transmission may span both slots of asubframe and may hop across frequency as shown in FIG. 4.

The PSS, SSS, CRS, PBCH, PUCCH and PUSCH in LTE are described in 3GPP TS36.211, entitled “Evolved Universal Terrestrial Radio Access (E-UTRA);Physical Channels and Modulation,” which is publicly available.

In an aspect, described herein are systems and methods for providingsupport within a wireless communication environment, such as a 3GPP LTEenvironment or the like, to facilitate multi-radio coexistencesolutions.

Referring now to FIG. 5, illustrated is an example wirelesscommunication environment 500 in which various aspects described hereincan function. The wireless communication environment 500 can include awireless device 510, which can be capable of communicating with multiplecommunication systems. These systems can include, for example, one ormore cellular systems 520 and/or 530, one or more WLAN systems 540and/or 550, one or more wireless personal area network (WPAN) systems560, one or more broadcast systems 570, one or more satellitepositioning systems 580, other systems not shown in FIG. 5, or anycombination thereof. It should be appreciated that in the followingdescription the terms “network” and “system” are often usedinterchangeably.

The cellular systems 520 and 530 can each be a CDMA, TDMA, FDMA, OFDMA,Single Carrier FDMA (SC-FDMA), or other suitable system. A CDMA systemcan implement a radio technology such as Universal Terrestrial RadioAccess (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) andother variants of CDMA. Moreover, cdma2000 covers IS-2000 (CDMA2000 1X),IS-95 and IS-856 (HRPD) standards. A TDMA system can implement a radiotechnology such as Global System for Mobile Communications (GSM),Digital Advanced Mobile Phone System (D-AMPS), etc. An OFDMA system canimplement a radio technology such as Evolved UTRA (E-UTRA), Ultra MobileBroadband (UMB), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM®, etc.UTRA and E-UTRA are part of Universal Mobile Telecommunication System(UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are newreleases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSMare described in documents from an organization named “3^(rd) GenerationPartnership Project” (3GPP). cdma2000 and UMB are described in documentsfrom an organization named “3^(rd) Generation Partnership Project 2”(3GPP2). In an aspect, the cellular system 520 can include a number ofbase stations 522, which can support bi-directional communication forwireless devices within their coverage. Similarly, the cellular system530 can include a number of base stations 532 that can supportbi-directional communication for wireless devices within their coverage.

WLAN systems 540 and 550 can respectively implement radio technologiessuch as IEEE 802.11 (WiFi), Hiperlan, etc. The WLAN system 540 caninclude one or more access points 542 that can support bi-directionalcommunication. Similarly, the WLAN system 550 can include one or moreaccess points 552 that can support bi-directional communication. TheWPAN system 560 can implement a radio technology such as Bluetooth (BT),IEEE 802.15, etc. Further, the WPAN system 560 can supportbi-directional communication for various devices such as wireless device510, a headset 562, a computer 564, a mouse 566, or the like.

The broadcast system 570 can be a television (TV) broadcast system, afrequency modulation (FM) broadcast system, a digital broadcast system,etc. A digital broadcast system can implement a radio technology such asMediaFLO™, Digital Video Broadcasting for Handhelds (DVB-H), IntegratedServices Digital Broadcasting for Terrestrial Television Broadcasting(ISDB-T), or the like. Further, the broadcast system 570 can include oneor more broadcast stations 572 that can support one-way communication.

The satellite positioning system 580 can be the United States GlobalPositioning System (GPS), the European Galileo system, the RussianGLONASS system, the Quasi-Zenith Satellite System (QZSS) over Japan, theIndian Regional Navigational Satellite System (IRNSS) over India, theBeidou system over China, and/or any other suitable system. Further, thesatellite positioning system 580 can include a number of satellites 582that transmit signals for position determination.

In an aspect, the wireless device 510 can be stationary or mobile andcan also be referred to as a user equipment (UE), a mobile station, amobile equipment, a terminal, an access terminal, a subscriber unit, astation, etc. The wireless device 510 can be cellular phone, a personaldigital assistance (PDA), a wireless modem, a handheld device, a laptopcomputer, a cordless phone, a wireless local loop (WLL) station, etc. Inaddition, a wireless device 510 can engage in two-way communication withthe cellular system 520 and/or 530, the WLAN system 540 and/or 550,devices with the WPAN system 560, and/or any other suitable systems(s)and/or devices(s). The wireless device 510 can additionally oralternatively receive signals from the broadcast system 570 and/orsatellite positioning system 580. In general, it can be appreciated thatthe wireless device 510 can communicate with any number of systems atany given moment. Also, the wireless device 510 may experiencecoexistence issues among various ones of its constituent radio devicesthat operate at the same time. Accordingly, device 510 includes acoexistence manager (CxM, not shown) that has a functional module todetect and mitigate coexistence issues, as explained further below.

Turning next to FIG. 6, a block diagram is provided that illustrates anexample design for a multi-radio wireless device 600 and may be used asan implementation of the radio 510 of FIG. 5. As FIG. 6 illustrates, thewireless device 600 can include N radios 620 a through 620 n, which canbe coupled to N antennas 610 a through 610 n, respectively, where N canbe any integer value. It should be appreciated, however, that respectiveradios 620 can be coupled to any number of antennas 610 and thatmultiple radios 620 can also share a given antenna 610.

In general, a radio 620 can be a unit that radiates or emits energy inan electromagnetic spectrum, receives energy in an electromagneticspectrum, or generates energy that propagates via conductive means. Byway of example, a radio 620 can be a unit that transmits a signal to asystem or a device or a unit that receives signals from a system ordevice. Accordingly, it can be appreciated that a radio 620 can beutilized to support wireless communication. In another example, a radio620 can also be a unit (e.g., a screen on a computer, a circuit board,etc.) that emits noise, which can impact the performance of otherradios. Accordingly, it can be further appreciated that a radio 620 canalso be a unit that emits noise and interference without supportingwireless communication.

In an aspect, respective radios 620 can support communication with oneor more systems. Multiple radios 620 can additionally or alternativelybe used for a given system, e.g., to transmit or receive on differentfrequency bands (e.g., cellular and PCS bands).

In another aspect, a digital processor 630 can be coupled to radios 620a through 620 n and can perform various functions, such as processingfor data being transmitted or received via the radios 620. Theprocessing for each radio 620 can be dependent on the radio technologysupported by that radio and can include encryption, encoding,modulation, etc., for a transmitter; demodulation, decoding, decryption,etc., for a receiver, or the like. In one example, the digital processor630 can include a CxM 640 that can control operation of the radios 620in order to improve the performance of the wireless device 600 asgenerally described herein. The CxM 640 can have access to a database644, which can store information used to control the operation of theradios 620. As explained further below, the CxM 640 can be adapted for avariety of techniques to decrease interference between the radios. Inone example, the CxM 640 requests a measurement gap pattern or DRX cyclethat allows an ISM radio to communicate during periods of LTEinactivity.

For simplicity, digital processor 630 is shown in FIG. 6 as a singleprocessor. However, it should be appreciated that the digital processor630 can include any number of processors, controllers, memories, etc. Inone example, a controller/processor 650 can direct the operation ofvarious units within the wireless device 600. Additionally oralternatively, a memory 652 can store program codes and data for thewireless device 600. The digital processor 630, controller/processor650, and memory 652 can be implemented on one or more integratedcircuits (ICs), application specific integrated circuits (ASICs), etc.By way of specific, non-limiting example, the digital processor 630 canbe implemented on a Mobile Station Modem (MSM) ASIC.

In an aspect, the CxM 640 can manage operation of respective radios 620utilized by wireless device 600 in order to avoid interference and/orother performance degradation associated with collisions betweenrespective radios 620. CxM 640 may perform one or more processes, suchas those illustrated in FIG. 11. By way of further illustration, a graph700 in FIG. 7 represents respective potential collisions between sevenexample radios in a given decision period. In the example shown in graph700, the seven radios include a WLAN transmitter (Tw), an LTEtransmitter (T1), an FM transmitter (Tf), a GSM/WCDMA transmitter(Tc/Tw), an LTE receiver (R1), a Bluetooth receiver (Rb), and a GPSreceiver (Rg). The four transmitters are represented by four nodes onthe left side of the graph 700. The four receivers are represented bythree nodes on the right side of the graph 700.

A potential collision between a transmitter and a receiver isrepresented on the graph 700 by a branch connecting the node for thetransmitter and the node for the receiver. Accordingly, in the exampleshown in the graph 700, collisions may exist between (1) the WLANtransmitter (Tw) and the Bluetooth receiver (Rb); (2) the LTEtransmitter (T1) and the Bluetooth receiver (Rb); (3) the WLANtransmitter (Tw) and the LTE receiver (R1); (4) the FM transmitter (Tf)and the GPS receiver (Rg); (5) a WLAN transmitter (Tw), a GSM/WCDMAtransmitter (Tc/Tw), and a GPS receiver (Rg).

In one aspect, an example CxM 640 can operate in time in a manner suchas that shown by diagram 800 in FIG. 8. As diagram 800 illustrates, atimeline for CxM operation can be divided into Decision Units (DUs),which can be any suitable uniform or non-uniform length (e.g., 100 μs)where notifications are processed, and a response phase (e.g., 20 μs)where commands are provided to various radios 620 and/or otheroperations are performed based on actions taken in the evaluation phase.In one example, the timeline shown in the diagram 800 can have a latencyparameter defined by a worst case operation of the timeline, e.g., thetiming of a response in the case that a notification is obtained from agiven radio immediately following termination of the notification phasein a given DU.

As shown in FIG. 9, Long Term Evolution (LTE) in band 7 (for frequencydivision duplex (FDD) uplink), band 40 (for time division duplex (TDD)communication), and band 38 (for TDD downlink) is adjacent to the 2.4GHz Industrial Scientific and Medical (ISM) band used by Bluetooth (BT)and Wireless Local Area Network (WLAN) technologies. Frequency planningfor these bands is such that there is limited or no guard bandpermitting traditional filtering solutions to avoid interference atadjacent frequencies. For example, a 20 MHz guard band exists betweenISM and band 7, but no guard band exists between ISM and band 40.

To be compliant with appropriate standards, communication devicesoperating over a particular band are to be operable over the entirespecified frequency range. For example, in order to be LTE compliant, amobile station/user equipment should be able to communicate across theentirety of both band 40 (2300-2400 MHz) and band 7 (2500-2570 MHz) asdefined by the 3rd Generation Partnership Project (3GPP). Without asufficient guard band, devices employ filters that overlap into otherbands causing band interference. Because band 40 filters are 100 MHzwide to cover the entire band, the rollover from those filters crossesover into the ISM band causing interference. Similarly, ISM devices thatuse the entirety of the ISM band (e.g., from 2401 through approximately2480 MHz) will employ filters that rollover into the neighboring band 40and band 7 and may cause interference.

In-device coexistence problems can exist with respect to a UE betweenresources such as, for example, LTE and ISM bands (e.g., forBluetooth/WLAN). In current LTE implementations, any interference issuesto LTE are reflected in the downlink measurements (e.g., ReferenceSignal Received Quality (RSRQ) metrics, etc.) reported by a UE and/orthe downlink error rate which the eNodeB can use to make inter-frequencyor inter-RAT handoff decisions to, e.g., move LTE to a channel or RATwith no coexistence issues. However, it can be appreciated that theseexisting techniques will not work if, for example, the LTE uplink iscausing interference to Bluetooth/WLAN but the LTE downlink does not seeany interference from Bluetooth/WLAN. More particularly, even if the UEautonomously moves itself to another channel on the uplink, the eNodeBcan in some cases handover the UE back to the problematic channel forload balancing purposes. In any case, it can be appreciated thatexisting techniques do not facilitate use of the bandwidth of theproblematic channel in the most efficient way.

Turning now to FIG. 10, a block diagram of a system 1000 for providingsupport within a wireless communication environment for multi-radiocoexistence management is illustrated. In an aspect, the system 1000 caninclude one or more UEs 1010 and/or eNodeBs 1040, which can engage inuplink and/or downlink communications, and/or any other suitablecommunication with each other and/or any other entities in the system1000. In one example, the UE 1010 and/or eNodeB 1040 can be operable tocommunicate using a variety resources, including frequency channels andsub-bands, some of which can potentially be colliding with other radioresources (e.g., a broadband radio such as an LTE modem). Thus, the UE1010 can utilize various techniques for managing coexistence betweenmultiple radios utilized by the UE 1010, as generally described herein.

To mitigate at least the above shortcomings, the UE 1010 can utilizerespective features described herein and illustrated by the system 1000to facilitate support for multi-radio coexistence within the UE 1010.For example, a channel monitoring module 1012, a channel qualityreporting module 1014, and a channel reporting adjustment module 1016may be implemented. The channel monitoring module 1012 monitors theperformance of communication channels for potential interference issues.The channel quality reporting module 1014 reports on the quality ofcommunication channels. The channel reporting adjustment module 1016 mayadjust the reporting on the quality of communication channels using themethods described below. The various modules 1012-1016 may, in someexamples, be implemented as part of a coexistence manager such as theCxM 640 of FIG. 6. The various modules 1012-1016 and others may beconfigured to implement the embodiments discussed herein.

From the perspective of a UE/mobile device, LTE is, by design, areceiving system. If transmission by another technology such as anIndustrial Scientific and Medical (ISM) radio like Bluetooth interfereswith LTE reception, the coexistence manager may stop the interferingtechnology to accommodate LTE. One parameter a UE has to measure LTEdownlink (DL) receiving performance is the channel quality indicator(CQI). The CQI value may be used and manipulated by a UE/coexistencemanager to manage coexistence between multiple radios on a UE.

In one aspect of the present disclosure, the value of CQI may be set tozero, thereby tricking an eNB to believe a UE is out of range for onecommunication technology (such as an LTE) in order to create gaps whichmay be used for communication by other technologies (such as an ISMradio). In another aspect of the present disclosure, the value of CQImay be reduced. Coexistence interference which fluctuates over time maycause a mismatch in link performance. The CQI may be filtered over aperiod of time and an average CQI reported, in order to compensate. Analternative may be to always report a CQI with the interference. Inanother aspect of the present disclosure, CQI may be boosted above whatit should be to include an error.

Setting CQI to zero may be used by a coexistence manager to create timegaps where LTE is rendered inactive, thereby allowing the coexistencemanager to allocate channel resources to another interfering technology,including Bluetooth (BT) operating in Advanced Audio DistributionProfile (A2DP) mode (audio mode) and wireless local area network (WLAN).In order to signal an evolved NodeB (eNodeB) to not schedule the user,and thereby create a gap during which the UE is not expected to processLTE downlink signals, the UE can send a CQI=0 value to the eNodeB. TheeNodeB will interpret CQI=0 as an out of range value which the eNodeBwill take to indicate that the UE is not in a position to receivedownlink grants. Such an indication would assist in creating an LTEdownlink gap. The UE sends a CQI=0 before the LTE-OFF interval to createthe gap and sends the correct CQI value just before the LTE-ON interval.The resulting gap may then be used for communication by an interferingtechnology. During the LTE-ON interval the LTE reception monitorsdownlink subframes for grants sent by the eNB. During the LTE-OFFinterval, LTE receptions are not expecting grants, so LTE does notmonitor downlink sub-frames these resources may be assigned to othertechnologies.

Reducing CQI is another technique which may be used by a coexistencemanager. In normal operation, CQI accounts for the coexistenceinterference in its estimate. If the loss in throughput (due to a lowerCQI value) is reasonable, a coexistence manager may rely on the CQI tocreate a compensating coexistence mitigation scheme. That is, if theloss is already accounted for, the rate will be set appropriately.

If interference is inconsistent or bursty (i.e., varies over time), atcertain times the CQI may indicate no interference even thoughinterference does exist at the time of transmission, thereby causing amismatch in link performance and potentially causing a “spiral of death”which results in a continuing drop in performance potentially resultingin a dropped call (see below). To avoid this situation, the UE mayaverage the CQI over a period of time (e.g., multiple subframes) tocapture the interference caused by coexistence. The time of averagingmay correspond to the time of HARQ (hybrid automatic repeat request),meaning the time spent to transmit a packet. Interference may beaveraged over a period of time (x ms). The UE may assume the sameinterference will be seen over the next x milliseconds. Alternatively,the UE may be conservative and send the CQI with the coexistenceinterference (i.e., the CQI value representing the worst performance) tothe eNodeB.

According to an aspect of the present disclosure, boosting CQI isanother technique available to a coexistence manager. Due to coexistenceissues, the coexistence manager may compromise LTE reception by allowinganother interfering technology to transmit. By adjusting the CQI valuereported to an eNodeB, a coexistence manager may allow a UE to achieve abetter LTE downlink throughput rate than would otherwise be available byreporting actual CQI, so long as “spiral of death” effects discussedbelow are avoided.

Typically, the eNodeB may run an outer loop for rate control to adjustthe CQI value to account for changes in transmission conditions fromwhen the CQI value was reported to the eNodeB by a UE to the time of thenext downlink grant. The eNodeB outer loop tracks the packet error rateover a period of time. The outer loop may add a CQIbackoff value to thereported CQI. The outer loop continually runs to adjust the CQIbackoffto an amount just sufficient for packet decoding. For example, if aparticular packet does not decode, the CQIbackoff increases by somevalue Δup (backoff increase). If a packet does decode, the CQIbackoffdecreases by some value Δdown (backoff decrease). The values Δup andΔdown may be chosen to keep a desired downlink packet error rate at asteady state. If downlink sub-frames to a UE are denied because ofcoexistence, the modulation coding scheme (MCS) allocated to the UE indownlink communications would decrease. If a coexistence manager isactively compromising/denying downlink sub-frames with a rate higherthan used by the outer loop, the MCS assigned to the UE will continue todrop to compensate until hitting the minimum MCS defined by the airinterface standard, e.g., 3GPP specification. This process is known as a“spiral of death” (SoD). The spiral of death may cause severe throughputloss and potential call drop.

The spiral of death may occur in the following manner. Assume an outerloop packet error rate target of 20%. If a coexistence managercompromises 30% of LTE downlink subframes, those denial rates create anerror rate unacceptable to the outer loop packet error rate, and the MCSwill be unable to lower sufficiently to achieve successful operation.Because the outer loop will never converge (i.e., achieve an acceptablepacket error rate), the spiral of death occurs.

In another example, the spiral of death may be avoided. Assume an outerloop packet error rate of 40% on the first transmission. If acoexistence manager is compromising 30% of LTE downlink subframes,because that denial rate is less than the outer loop packet error rate,the outer loop will drop the MCS to a point where the packet error rateis only 10%, such that the combined rates of error of the MCS and denialof LTE reach the targeted 40%. Thus the MCS and coexistence LTE denialwill converge to achieve equilibrium and successful operation. In thisexample, no spiral of death effects will be seen.

The UE/coexistence manager may adjust its CQI reporting to avoid thespiral of death and manage coexistence issues. For example, if the UEreports a higher than actual CQI to the eNodeB, the eNodeB will apply anextra backoff due to the spiral of death process. Thus, the total CQIremains almost unchanged. The UE, however, typically does not know thevalues of As applied by the eNodeB and whether or not the spiral ofdeath is occurring. Accordingly, the proper CQI value should somehow beestimated.

A series of equations may be used to determine CQI reporting sufficientto avoid spiral of death issues when creating transmission gaps forcoexistence management. Define:

y: the denial rate for LTE downlink

x: the packet error rate used by eNodeB outer loop

Cr(n): reported CQI at time n

Ct(n): true CQI at time n for subframes with good quality

Co(n): CQI determined by eNodeB at time n (accounting for the eNodeBbackoff value).

Co(n) can be determined by mapping the downlink decoded data rate attime n to a CQI value using the CQI table in air interface standard,(e.g., the 3GPP specification) and a number of resource blocks (RBs)allocated. The actual decoded data rate can be the average rate over oneCQI report interval.

In the absence of coexistence interference, the backoff, B(n), appliedby the outer loop is:

B(n)=Σ_(i=1−n)gi, where

gi=Δup with probability x or Δdown with probability (1−x). In theabsence of coexistence interference, the outer loop will converge when:

Δup·x=Δdown·(1−x), that is

${\Delta \; {down}} = {{( \frac{x}{1 - x} ) \cdot \Delta}\; {up}}$

The eNodeB CQI, Co(n), is calculated as:

Co(n)=Cr(n)−B1−B2(n)

where B1 is a backoff accumulated by the outer loop due to timevariation in the channel, and B2(n) is the extra backoff added by theouter loop when the targeted packet error rate is not met due todownlink denials. If the coexistence manager denies y % of the LTEdownlink sub-frames where y>x:

${{E( {B\; 2(n)} )} = {{n( \frac{y}{1 - x} )}\Delta \; {up}}},$

where E(z) is the expected value of z the backoff will increase overtime causing the spiral of death. To avoid this, the UE may report atrue CQI plus error:

$\begin{matrix}{{{Cr}(n)} = {{{Ct}(n)} + \lbrack {{{Cr}( {n - 1} )} - {{Co}( {n - 1} )}} \rbrack}} \\{= {{{Ct}(n)} + {B\; 1} + {B\; 2( {n - 1} )}}}\end{matrix}\quad$

hence,

$\begin{matrix}{{{Co}(n)} = {{{Ct}(n)} - {B\; 2(n)} + {B\; 2( {n - 1} )}}} \\{{= {{{Ct}(n)} - v}},{{where}\mspace{14mu} v\mspace{14mu} {has}\mspace{14mu} a\mspace{14mu} {mean}\mspace{14mu} {{of}( \frac{y}{1 - x} )}\Delta \; {up}}}\end{matrix}{\quad\quad}$

In this manner, the likely backoff to be applied by the outer loop atthe eNodeB is compensated for in the CQI reported by the UE. Thus, theloss in throughput is limited and does not grow with n, thereby avoidingthe spiral of death while adjusting CQI values to allow for coexistencemanagement.

As shown in FIG. 11 a UE may alter a channel measurement report tocreate a communication gap in a first radio access technology (RAT), asshown in block 1102. A UE may communicate using a second RAT during thecreated communication gap, as shown in block 1104.

As shown in FIG. 12 a UE may alter a channel measurement report of afirst radio access technology (RAT) based on interference from a radioof a second RAT, as shown in block 1202. A UE may report the alteredchannel measurement report to a serving cell, as shown in block 1202.

A UE may comprise means for altering a channel measurement report tocreate a communication gap in a first radio access technology. In oneaspect, the aforementioned means may be the channel reporting adjustmentmodule 1016, the coexistence manager 640, the memory 272, and/or theprocessor 270 configured to perform the functions recited by theaforementioned means. The UE may also comprise means for communicatingusing a second RAT during the created communication gap. In one aspect,the aforementioned means may be the antennae 252, the coexistencemanager 640, the memory 272, and/or the processor 270 configured toperform the functions recited by the aforementioned means. In anotheraspect, the aforementioned means may be a module or any apparatusconfigured to perform the functions recited by the aforementioned means.

A UE may comprise means for altering a channel measurement report of afirst radio access technology (RAT) based on interference from a radioof a second RAT. In one aspect, the aforementioned means may be thechannel reporting adjustment module 1016, the receive data processor260, the coexistence manager 640, the memory 272, and/or the processor270 configured to perform the functions recited by the aforementionedmeans. The UE may also comprise means for reporting the altered channelmeasurement report to a serving cell. In one aspect, the aforementionedmeans may be the channel quality reporting module 1014, the antennae252, the memory 272, and/or the processor 270 configured to perform thefunctions recited by the aforementioned means. In another aspect, theaforementioned means may be a module or any apparatus configured toperform the functions recited by the aforementioned means.

FIG. 13 shows a design of an apparatus 1300 for a UE. The apparatus 1300includes a module 1302 to alter a channel measurement report to create acommunication gap in a first radio access technology (RAT). Theapparatus also includes a module 1304 to communicate using a second RATduring the created communication gap. The modules in FIG. 13 may beprocessors, electronics devices, hardware devices, electronicscomponents, logical circuits, memories, software codes, firmware codes,etc., or any combination thereof.

FIG. 14 shows a design of an apparatus 1400 for a UE. The apparatus 1400includes a module 1402 to alter a channel measurement report of a firstradio access technology (RAT) based on interference from a radio of asecond RAT. The apparatus also includes a module 1404 to report thealtered channel measurement report to a serving cell. The modules inFIG. 14 may be processors, electronics devices, hardware devices,electronics components, logical circuits, memories, software codes,firmware codes, etc., or any combination thereof.

The examples above describe aspects implemented in an LTE system.However, the scope of the disclosure is not so limited. Various aspectsmay be adapted for use with other communication systems, such as thosethat employ any of a variety of communication protocols including, butnot limited to, CDMA systems, TDMA systems, FDMA systems, and OFDMAsystems.

It is understood that the specific order or hierarchy of steps in theprocesses disclosed is an example of exemplary approaches. Based upondesign preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged while remainingwithin the scope of the present disclosure. The accompanying methodclaims present elements of the various steps in a sample order, and arenot meant to be limited to the specific order or hierarchy presented.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the aspects disclosed herein may be implemented aselectronic hardware, computer software, or combinations of both. Toclearly illustrate this interchangeability of hardware and software,various illustrative components, blocks, modules, circuits, and stepshave been described above generally in terms of their functionality.Whether such functionality is implemented as hardware or softwaredepends upon the particular application and design constraints imposedon the overall system. Skilled artisans may implement the describedfunctionality in varying ways for each particular application, but suchimplementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with theaspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such the processorcan read information from, and write information to, the storage medium.In the alternative, the storage medium may be integral to the processor.The processor and the storage medium may reside in an ASIC. The ASIC mayreside in a user terminal. In the alternative, the processor and thestorage medium may reside as discrete components in a user terminal.

The previous description of the disclosed aspects is provided to enableany person skilled in the art to make or use the present disclosure.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other aspects without departing from the spirit or scope ofthe disclosure. Thus, the present disclosure is not intended to belimited to the aspects shown herein but is to be accorded the widestscope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method of wireless communication, comprising:altering a channel measurement report to create a communication gap in afirst radio access technology; and communicating using a second radioaccess technology during the created communication gap.
 2. The method ofclaim 1 in which the second radio access technology comprises anIndustrial Scientific and Medical modem and the first radio accesstechnology comprises a Long Term Evolution modem.
 3. An apparatus forwireless communications, comprising: means for altering a channelmeasurement report to create a communication gap in a first radio accesstechnology; and means for communicating using a second radio accesstechnology during the created communication gap.
 4. A computer programproduct configured for wireless communication, the computer programproduct comprising: a non-transitory computer-readable medium havingnon-transitory program code recorded thereon, the non-transitory programcode comprising: program code to alter a channel measurement report tocreate a communication gap in a first radio access technology; andprogram code to communicate using a second radio access technologyduring the created communication gap.
 5. An apparatus configured forwireless communication, the apparatus comprising: a memory; and at leastone processor coupled to the memory, the at least one processor beingconfigured: to alter a channel measurement report to create acommunication gap in a first radio access technology; and to communicateusing a second radio access technology during the created communicationgap.
 6. The apparatus of claim 5 in which the second radio accesstechnology comprises an Industrial Scientific and Medical modem and thefirst radio access technology comprises a Long Term Evolution modem.